Wisconsin Law Journal – WI Legal News & Resources Wisconsin Legal News & Resources

Petitioner-Appellant Exelon Corporation (“Exelon”) appeals from a decision of the United States tax court which upheld a determination by the Commissioner of Internal Revenue that Exelon is liable for a deficiency of $431,174,592 for the 1999 tax year and $5,534,611 for the 2001 tax year.

For decades, Wisconsin courts have deferred to administrative agencies’ interpretations of law. In a recent decision - Tetra Tech EC, Inc. v. DOR, the Wisconsin Supreme Court effectively ended this practice: “We have also decided to end our practice of deferring to administrative agencies’ conclusions of law.”